I had unusual chest pain today and would like some thoughts on it

It wasn't like the gas pain that I get sometimes or like the pain associated with pleurisy or costochondritis, this was a really sharp, piercing type of pain deep in my left chest under the breast. The pain lasted a few seconds, then left, then came, then left, then came again and left. The whole episode wasn't over 5 minutes.

I thought about what to do and then thought, after it was all over, that it was nothing, so did nothing.

Have any of you experience this type of pain? It was so different than usual. Maybe we all have so much pain that we ignore really important pain. What do you think? Tonight I'm just extra tired and really shaky right now.